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    <title>Document</title>
    <script>
        var r = parseFloat(prompt("请输入圆锥的底面半径：",5));
        var h = parseFloat(prompt("请输入圆锥的高：",4));
        var PI = 3.14;
        alert("圆锥体积="+ PI*r*r*h/3)
    </script>
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